COMP1511 Revision Linked Lists Exercises

Download list_sum.c here, or copy it to your CSE account using the following command:

cp -n /web/cs1511/20T1/activities/list_sum/list_sum.c .

Your task is to add code to this function in list_sum.c:

// Return the sum of the elements in the linked list pointed by head
int sum(struct node *head) {

    // PUT YOUR CODE HERE (change the next line!)
    return 42;

}

Add code to sum so that its returns the sum of the list.

For example if the linked list contains these 8 elements:

1, 7, 8, 9, 13, 19, 21, 42

sum should return 120 because 1 + 7 + 8 + 9 + 13 + 19 + 21 + 42 = 120.

Testing

This main function:

• converts the command-line arguments to a linked list
• assigns a pointer to the first node in the linked list to head
• calls list_sum(head)
• prints the result.

Do not change this main function. If you want to change it, you have misread the question.

Your list_sum function will be called directly in marking. The main function is only to let you test your list_sum function

Here is how you use main function allows you to test list_sum:

dcc list_sum.c -o list_sum
./list_sum 1 2 4 8 16 32 64 128 256
511
./list_sum 2 4 6 5 8 9
34
./list_sum 13 15 17 17 18
80
./list_sum 42 4
46
./list_sum
0

Assumptions/Restrictions/Clarifications.

sum should not change the linked list it is given. Your function should not change the next or data fields of list nodes.

sum should not use arrays.

sum should not call malloc.

sum should not call scanf (or getchar or fgets).

sum should not print anything. It should not call printf.

Do not change the supplied main function. It will not be tested or marked.

When you think your program is working you can use autotest to run some simple automated tests:

1511 autotest list_sum

Download list_count_favourite.c here, or copy it to your CSE account using the following command:

cp -n /web/cs1511/20T1/activities/list_count_favourite/list_count_favourite.c .

Your task is to add code to this function in list_count_favourite.c:

// Return the number of elements divisible by 17 in the linked list
int count_favourite(struct node *head) {

    // PUT YOUR CODE HERE (change the next line!)
    return 42;

}

Add code to count_favourite so that its returns the number of elements divisible by 17 in the list.

For example if the linked list contains these 8 elements:

51, 7, 8, 9, 34, 19, 34, 42

count_favourite should return 3 because 51, 34 and 34 are divisible by 17.

Testing

This main function:

• converts the command-line arguments to a linked list
• assigns a pointer to the first node in the linked list to head
• calls list_count_favourite(head)
• prints the result.

Do not change this main function. If you want to change it, you have misread the question.

Your list_count_favourite function will be called directly in marking. The main function is only to let you test your list_count_favourite function

Here is how you use main function allows you to test list_count_favourite:

dcc list_count_favourite.c -o list_count_favourite
./list_count_favourite 51 7 8 9 34 19 34 42
3
./list_count_favourite 2 4 6 5 8 9
0
./list_count_favourite 17 34 51 68 85 102 119 136 153
9
./list_count_favourite
0

Assumptions/Restrictions/Clarifications.

count_favourite should not change the linked list it is given. Your function should not change the next or data fields of list nodes.

count_favourite should not use arrays.

count_favourite should not call malloc.

count_favourite should not call scanf (or getchar or fgets).

count_favourite should not print anything. It should not call printf.

Do not change the supplied main function. It will not be tested or marked.

When you think your program is working you can use autotest to run some simple automated tests:

1511 autotest list_count_favourite

Download list_get_nth.c here, or copy it to your CSE account using the following command:

cp -n /web/cs1511/20T1/activities/list_get_nth/list_get_nth.c .

Your task is to add code to this function in list_get_nth.c:

// Return the n-th element of linked list.
// n == 0 returns first element, n == 1, second element, ....
int get_nth(int n, struct node *head) {

    // PUT YOUR CODE HERE (change the next line!)
    return 42;

}

Add code to get_nth so that its returns the n-th element the linked element of the linked list.

The elements are counted in the same manner as array elements (zero-based), so the first element in the list is regarded as at position 0, the second element position 1 and so on.

get_nth can assume that the list contains at least n + 1 elements.

For example if the linked list contains these 8 elements:

1, 7, 8, 9, 13, 19, 21, 42

if n is 1 get_nth should return 7.

Testing

This main function:

• converts the first command-line argument to n
• converts the remaining command-line arguments to a linked list
• assigns a pointer to the first node in the linked list to head
• calls list_get_nth(n, head)
• prints the result.

Do not change this main function. If you want to change it, you have misread the question.

Your list_get_nth function will be called directly in marking. The main function is only to let you test your list_get_nth function

Here is how you use main function allows you to test list_get_nth:

dcc list_get_nth.c -o list_get_nth
./list_get_nth 0  5 6 7 8
5
./list_get_nth 1  5 6 7 8
6
./list_get_nth 2  5 6 7 8
7
./list_get_nth 3  5 6 7 8
8
./list_get_nth 0  42
42

Assumptions/Restrictions/Clarifications.

get_nth can assume n is non-negative.

get_nth can assume the linked list contains at least n + 1 elements.

get_nth should not change the linked list it is given. Your function should not change the next or data fields of list nodes.

get_nth should not use arrays.

get_nth should not call malloc.

get_nth should not call scanf (or getchar or fgets).

get_nth should not print anything. It should not call printf.

Do not change the supplied main function. It will not be tested or marked.

When you think your program is working you can use autotest to run some simple automated tests:

1511 autotest list_get_nth